This primary goal of this revised R34 application is to develop and conduct an initial evaluation of a modified cognitive-behavioral treatment (m-CBT) for depressed adolescents with histories of interpersonal trauma. A substantial number of adolescents retain their diagnoses or remain symptomatic following psychosocial or pharmacotherapy for depression. Notably, depressed adolescents with histories of trauma have been found to be less responsive to cognitive-behavioral therapy (CBT) for depression than non-exposed adolescents. Interpersonal trauma has been identified as a prominent developmental pathway to major depressive disorder and is prevalent among referrals to community clinics;thus, addressing the needs of this "treatment resistant" group is a high public health priority. In order to address the needs of this "treatment resistant" group, we propose to modify a cognitive-behavioral protocol that has been shown to be efficacious in prior clinical trials. Treatment modifications are based on the hypothesis that standard CBT does not address two factors central to depression in trauma-exposed youth: 1.) deficits in executive function;and 2.) trauma-related cognitions. First, deficits in executive functioning (e.g., attention, interference control, set shifting) found among traumatized youth are hypothesized to interfere with skill acquisition in CBT. To this end, the usual CBT modules will be modified to include empirically-supported interventions targeting executive function (e.g., attention control training, mindfulness-based cognitive interventions). Second, trauma-exposed individuals have been shown to endorse specific trauma-related maladaptive cognitions that are not typically targeted by CBT. To this end, the treatment will target both depressive automatic thoughts and trauma-related cognitions. Because a history of interpersonal trauma is prevalent among depressed adolescents in community clinics, this project uses a deployment-focused model of treatment development in order to create a "clinic-ready" intervention. To this end, the treatment will be developed and tested in a community mental health center with community clinicians and referred adolescents. The study involves two phases;the first involves pilot testing of the treatment manual with 8 referred adolescents. Acceptability, satisfaction, treatment adherence, and pre- post change in depressive symptoms will be examined. Following manual refinement, a randomized controlled trial under clinically-representative conditions will be conducted with a referred sample of 60 adolescents with a primary depression diagnosis and a history of interpersonal trauma. Adolescents will be randomized to the new intervention (m-CBT) or to an eclectic treatment-as-usual condition. Changes in depressive symptoms, global functioning, and cognitive processes (executive functions and trauma-related cognitions) will be evaluated between pre and post-treatment, and at 3-month follow-up. Linear mixed models with repeated measures will be used to evaluate the effects of treatment. Major depression affects approximately 1 in 6 adolescents during the teen years and results in increased risk for suicide, substance abuse, early childbearing, and school failure. Child interpersonal trauma is a well- documented pathway to major depression. Because youth exposed to interpersonal trauma are less likely to respond favorably to existing depression treatments, this project will develop and evaluate a new treatment for depressed adolescents with interpersonal trauma histories.